SVD, do you have any evidence of the A or are you basing that on things looking "funny" when she FT'd you? I'm not sure that's enough to hang your hat on. Normally we say not to snoop but if you really must know then get serious about it and hire a PI. Once you've verified it's true, then stop snooping because you found out what you needed to. I'll just warn you that if W finds out you are snooping she will go deeper undercover with her activities and it'll be even harder to find anything out. And she will more than likely deny, deny, deny.
I have no smoking bullet but early on (early January) I did see some text messages to her friend referencing "OMG moment, his name, and if they had talked again 'since'. She is always on her phone, gone almost every weekend staying over at 'friends' and what not. It's fairly obvious what is going on.
